As previously reported in this newsletter (1), the question of the patentability of technology based on the use of human embryonic stem cells (hESC) was considered in the Court of Justice of the European Union (CJEU) referral Brüstle v Greenpeace (C-34/10) in October 2011. The CJEU referral related to a German national patent granted to neuroscientist Oliver Brüstle in 1999, for a method of turning mammalian embryonic stem (ES) cells into neurons.

Following the ruling of the CJEU, it was then left for the German courts to decide on the allowability of the original patent. In these proceedings, the German Federal Court of Justice ruled the patent could be maintained if it included a general disclaimer excluding the destruction of human embryos.

Parallel opposition proceedings have also been on going at the European Patent Offi ce (EPO) with respect to the corresponding European patent. In contrast to the German case, the EPO opposition division have revoked the European patent.

An equivalent amendment to that made on the German national case was rejected on the grounds of ‘added matter’ ie, the claims were considered to contain subject matter not disclosed in the original patent application.

The EPO has therefore avoided consideration of moral issues surrounding the patentability of inventions relating to human ES cells.

The decision of the Opposition Division is open to appeal. If the case goes to appeal and the added matter issue is resolved, the morality issues may be reconsidered, either by the Technical Board of Appeal or by the Opposition Division (if the case is remitted). However, it is likely to be a matter of years before this takes place.

In the meantime, a separate referral has been made to the CJEU on a stem cell related matter.

The UK’s High Court has made a referral to the CJEU to clarify if human ‘parthenotes’ fall under the definition of a human embryo under the Biotechnology Directive (2).

Parthenotes are activated unfertilised oocytes which may be used for the production of human stem cell lines.

To quote from an article in Scientific American (3): “Human embryonic stem cells typically come from fertilized eggs. In 2007, however, scientists at International Stem Cell, a California-based biotech firm, reported the first successful creation of human stem cell lines from unfertilized eggs. They used a process called parthenogenesis, in which researchers use chemicals to induce the egg to begin developing as if it had been fertilized. The egg – called a parthenote -behaves just like an embryo in the early stages of division. Because it contains no genetic material from a father, however, it cannot develop into a viable fetus.”

The US High Court referral concerns an appeal brought by International Stem Cell Corporation (ISCC) against a decision made by the UK Intellectual Patent Offi ce (UK IPO) in 2012 to reject two patent applications over a method for inducing pluripotent stem cells from human eggs that have undergone parthenogenesis.

The UK IPO’s decision said: “A parthenogenetically-stimulated human oocyte is considered, on the basis of the Brüstle judgment to be capable of commencing the process of development even if it is not able to complete this development”.

The Brüstle judgment (CJEU referral C-34/10, mentioned above) defined a ‘human embryo’ under European law as “any [fertilised] human ovum [...] if that fertilisation is such as to commence the process of development of a human being”.

It further said that this definition includes “a non-fertilised human ovum whose division and further development have been stimulated by parthenogenesis”.

ISCC argued that the key question was what the CJEU meant by “capable of commencing the process of development of a human being”. It was unclear whether this referred to an entity that could in fact develop into a human being or something that could start the process of becoming a human being but was unable to complete that process.

A parthenote is capable of developing into a blastocyst-like structure but cannot develop into a human being because it lacks paternal DNA. On the evidence before the High Court, human parthenotes were shown to develop to the blastocyst stage, over about five days, but after that period the requirement for paternal genes became acute and the oocyte did not develop further, and never to term.

There was, however, no consensus on the scientific evidence as to the developmental potential of parthenotes put before the CJEU in the Brüstle judgment.

The High Court judge therefore found that the law was not acte clair on this point, and so there shall be another reference to the CJEU on patentability of stem cells, specifically on the patentability of unfertilised human ova.